Grate for steam-boiler furnaces



(No Model.) 3 Sheets-Sheet 2.

J. VAN DEVELDE. GRATE FOR STEAM BOILER FURNACES, &c.

Patented Nov. 19, 1895.

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JOHN VAN DEVELDE, OF CLEVELAND, OHIO.

GRATE FOR STEAM-BOILER FURNACES, C.

SPECIFICATION forming part of Letters Patent No. 549,948, dated November19, 1895.

Applioation filed OctoberlZ, 1594.

To all whom it may concern:

Be it known that I, J OHN VANDEVELDE, a citizen of the United States,residing at Cleveland, in the county of Ouyahoga, State of Ohio, haveinvented certain new and useful Improvements in Steam-Boiler Furnaces,of which the following, with the acco1npanying drawings, is aspecification.

My invention relates more especially to steam -boiler downward-draftfurnaces in which hollow grate-bars or tubes, through which water fromthe boiler circulates, are used.

The object of my invention is an improved construction of steam-boilerfurnaces employing tubular grate-bars connected with a water-chamberthat in turn is connected with the boiler, whereby a more perfectcombustion of fuel is obtained and the steam-generating capacity of thefurnace is increased.

lVith these objects in view my invention consists in the novel featuresof construction and combination of parts described herein and defined inthe claim.

In the drawings, Figure 1 is a longitudinal section of my invention.Fig. 2 is a front view. Fig. 3 is a central longitudinal section of thewater-chamber. Fig. 418 an enlarged longitudinal section of the frontend of the hollow grate-bars and inolosed circulation tube. Fig. 5 is anenlarged perspective of a broken section of the front end of thecirculation-tube, and Fig. 6 is a cross-section of one of the hollowgrate-bars and the inclosed circulation-pipe on the line 6 6 of Fig. 4.Fig. 7 is a longitudinal section of a modified arrangement of myinvention.

In the accompanying drawings, A is the boiler, which is of the usualconstruction, having flues therethrough longitudinally, whichcommunicate with the space below the smokestack A.

B is the furnace outer wall, which is of any desired construction, and Ois a baffle-wall extending across the furnace from the boiler to thefloor of the furnace. There is an opening 0 through thebaffle-wall,which forms an escape for the products of combustion fromthe fire.

D is a division-wall.

E is awater-chamber which preferably corresponds to the widthof thegrate, and it Serial No. 525,665. (No model.)

opens into the boiler A through the connection F.

The lower upward-burning grate G, of any construction, is supported bythe bafile-wall O and the flange or fillet h of the furnacefront H.

The space I below the grate G is the ash-pit.

I I are the doors to the ash-pit.

The upper downward-burning grate consists of a series of tubular orhollow bars K K arranged horizontally with a slight slant, asillustrated. These tubular bars are closed at their front ends byscrew-caps k 70, and their back ends are screwed into the front side ofthe water-chamber E. The front ends of the tubular bars K are supportedby flanges h and h. The space L between the upper and the lower gratesforms a combustion-chamber.

M lWI are fire-doors that open to the firespace above the lower grateand to the con1- bustion-chamber.

N N are fire-doors that open to the firespace above the upper grate.

Below the upper fire-holes there is preferably placed a fillet h, overwhich the stoking is done for the upper fire, and limits the stokingback of said fillet to protect the front ends of the tubular grate-barsK.

M are doors which open access to the cap ends 70 for repairs or otherpurposes.

WVithin the tubular bars K K are circulation-tubes P P, the front endsof which are held free of the inside of the caps k by means of thebraces or supports 19, and they are held free of the sides of thetubular bars K by means of the braces 10. The circulating-tubes extendinto the water-chamber E, preferably to a point back of the centerthereof, as illustrated.

I have illustrated two horizontal series of suppplemental tubular barsK, having therein circulating-tubes P, the supplemental tubular barsopening into the water-chamber E and having their front ends closed bycaps 70, the circulating-tubes P being held free of the inside of thetubular bars K and extending into the water-chamber E, in all respectslike the tubular bars K and the circulatingpipes P; but they extendforward only so far, or not so far, as the baffle-wall G. These'may beemployed to increase the tubular heatingsurface or they may be omitted.

In the use of my invention stoking is done through the doors N N for theupper grate and through the doors M M for the lower grate. The space Lbetween the upper and lower grates forms a combustion-chamber. Airpasses downward through the upper grate, as indicated by the arrow 7',and upward through the lower grate, as indicated by the arrow 8. Thedraft passes through the escape C of the baffle-wall C, up among thetubular bars K and K, around the connection F, and through theboiler-fines, as indicated by the arrows t t. The colder water from theboiler finds its way down the back side of the connection F to the outerback part of the water-chamber E. The cooler water then passes into andthrough the circulating-tubes P P and comes back heated to a higherdegree around the circulatingtubes and back to the boiler through thefront part of the water-chamber E and the connection F. This circulationis induced by the Varying temperature of the water and the heat appliedto the tubular bars K and K.

The arrangement of my invention, as illustrated by Fig. 7, may beemployed when a less tubular heating-surface is required than by eitherof the constructions hereinbefore referred to. The water-chamber E isplaced immediately back of the fire-box at the wall 0, and theconnection F is connected to the boiler immediately above. The tubulargratebars K and circulating-tubes P are in all respects like thosehereinbefore described. As the boiler-front and fire and ash doors ofthe modification are the same as in the other form illustrated, the sameparts are given the same reference characters in Fig. 7 as in the otherfigures.

In the form illustrated by Fig. 7 the draft passes through the escape 0along the under side of the boiler, and through the boilerflues, asindicated by the arrows u in said figure.

\Vhat I claim as my invention, and desire to secure by Letters Patent,is-

The combination, in a steam-boiler furnace, of a water-chamber having anopening for connection with a boiler, a bathe-wall extending laterallythrough the furnace from the boiler to the floor of the furnace, anescape opening through the bafiie-wall, an upward burning grateextending from the bafile-wall below the escape opening thercthroughforwardly to the furnace front, a downwardly burning grate consisting oftubular grate bars, said tubular grate-bars being closed at their frontend and opening into said waterchamber at their back end, andcirculation tubes having both ends open, said circulation tubes beingwithin the tubular gratebars and projecting into the water chamber,substantially as specified.

In testimony whereof I ailix my signature in the presence of twowitnesses.

JOHN VAN DEVELDE. \Vitnesses:

J. A. OSBORNE, JNO. G. COMPTON.

